A printer including a recording head configured to eject ink supplied from an ink cartridge through nozzles is known in the art. For example, Japanese Patent Application Publication No. 2016-185650 discloses an ink cartridge configured to be attached to a cartridge attachment section provided at a main body of a printer. In a state where the ink cartridge is attached to the cartridge attachment section, an ink needle provided at the cartridge attachment section is inserted into a tubular ink supply portion provided at the ink cartridge. Thus, ink can be supplied from the ink cartridge to a recording head through the ink needle. The cartridge attachment section is provided with a hollow cylindrical guide portion at a position around the ink needle. During attachment process of the ink cartridge to the cartridge attachment section, the tubular ink supply portion is guided by the hollow cylindrical guide portion. Accordingly, the ink needle is introduced into an inner space of the ink supply portion.